Holding arrangements for optical elements are used in optical systems. The precision desired for mounting is generally dependent on the respective purpose of use.
An assembly for mounting an optical component relative to a carrier via at least three articulation points arranged at the outer circumferential region of the optical element is known from WO 2007/017013 A2, the optical element being held in a force-fitting manner by elastically resilient elements via the articulation points in at least one direction. The elastically resilient elements are located in this case in mounting device which hold the optical element in a statically determined manner.
An adjustable mount for a cylindrical lens in an optical system, for example the optical system of a laser printer, is known from U.S. Pat. No. 5,220,460. The mount includes a carrier element which is arranged perpendicularly to the optical axis (z axis) and has a flat face on which the cylindrical lens rests under the action of a constant force. A radius of curvature of the cylindrical lens is referred to in U.S. Pat. No. 5,220,460 as the y axis. An axis extending parallel to an axial direction of the cylindrical lens is referred to as the x direction. The adjustable mount is intended to allow a rotational movement about the optical axis and a translational movement in the direction of curvature for an adjustment. For this purpose, the cylindrical lens is mounted at two corners opposing each other in the x-y plane by a rib acting as a joint, a spring element and two set screws. Tilting about the two axes extending perpendicularly to the optical axis is on the other hand to be sufficiently ensured by the flat face on which the cylindrical lens rests for application in a laser printer.
Optical elements are also used in material processing devices, for example in laser annealing devices. An optical system of this type is described for example in WO 2006/066706. In devices of this type, a laser beam is used in order to fuse a layer for example, in particular a silicon layer, onto a substrate. In this case, the laser beam impinges onto the layer to be fused as a very narrow line beam. The layer and the laser beam are displaced relative to each other transversely to a line formed by the laser beam, so that the laser beam is guided in a planar manner over the substrate, which is known as the “panel”.
As these devices illuminate the panel with a long, but very narrow field, cylindrical lenses, i.e. lenses having just one direction of curvature, are used.
Applications of this type generally demand very high precision. To prevent or at least to keep low deformations on account of heating of the system, it is known to use materials having a low coefficient of thermal expansion, for example Invar. However, materials of this type can be very expensive.